I have always given my kids plenty of unstructured time, because I grew up that way and have very good memories of it. Because of this, both of my kids are more content - they can find ways to be happy, even when things do not go as planned (like when we lost electricity for a couple hours recently). The funny thing about this is that when my son was in preschool, one of his teachers told me, "We use time outs to correct behavior, but they don't work with your son, because very soon he is as happy in time out as he was while playing."